NetBrain discovery has little affects on the live network. NetBrain uses SNMP query to find a device hostname, vendor, model, IOS version and etc. However NetBrain uses CLI command instead of SNMP to retrieve the live data such as configurations and route tables. Some of our customers have a large network up to 10000 network devices and up to now no customer complain that NetBrain discovery has big any noticeable affect on their live network.